<table> <td>cell1</td> <td>cell2</td> </table>
I found out that these tags work on ie8, firefox 11 and chrome, but are not sure if it is really by standards and works in all major browsers.
All browsers accept "quirks" in the HTML layout and will display a "best guess" based on what they find. But in HTML specs, the tag is <tr> DEFINITELY required - whether it works or not, you should always use the correct HTML!
<tr>
Check early, check often!
http://validator.w3.org/
<tr>, , <table>, , .
<table>